Download Subject: Precision Optics II Grade: 10

Subject: Precision Optics II Grade: 10-11
Unit #: 1
Title: Lens Function & Design
UNIT OVERVIEW: Students are introduced to the nature of light, glass, and the interplay between the two in order to understand how optical
elements are designed and assembled together to create quality images. Students will understand optics and engineering content, which is
embedded throughout the year, so that students build on the fundamentals of advanced manufacturing processes learned in Precision Optics I.
Students develop habits of mind and skills necessary to manufacture, test, and evaluate a finished good, based on customer specifications.
STAGE ONE: Identify Desired Results
Established Goals (CDOS)
Long-Term Transfer Goal
Standard 1: Students will be
knowledgeable about the world
of work […] and relate personal
skills, aptitude and abilities to
future career decisions.
Established Goals/Standards
Standard 2: Students will
demonstrate how academic
knowledge and skills are applied
in workplace and other settings.
Standard 3a: Students will
demonstrate mastery of the
foundation skills and
competencies essential for
success in the workplace.
Standard 3b: Students who
choose a career major will
acquire the career specific
technical knowledge/skills to
progress toward gainful
employment, career
advancement and success in
postsecondary programs.
East High School, Rochester, NY
At the end of this unit, students will use what they have learned to independently… examine ray diagrams for several optics systems and
evaluate and compare the predicted image quality created by each optic with special attention paid to the type and severity of first
order aberrations. Students will construct an illustrated essay. This essay will indicate the student’s level of understanding about how
lenses are designed to control light.
Enduring Understandings
Meaning
Essential Questions
Students will understand that…
 Optics is the science of controlling light.
 Simple rays are used by engineers and lens designers to
illustrate the path of light through an optic.
 The performance of a lens (system) depends on each lens’
shape, orientation, glass type, and alignment within the system.
 Real lens systems are designed to minimize deviations from
ideal, but every system creates images with some degree of
aberration.
Students will consider such questions as…
1. How do we choose the right optic to make light do what we
want?
2. Why does curve and composition of the glass matter?
3. What can we “get away with” when designing optics?
4. How do optical designers maximize the performance of an
optical system?
Acquisition
What knowledge will students learn as part of this unit?
 Light is a packet of massless radiant energy that travels, in a
vacuum, at the cosmic speed limit, c. c = 300,000,000 m/s =
786,000 mph, 7.5 times around the Earth/s, to the moon in 1.3
seconds. A single packet is called a photon.
 The Electromagnetic Spectrum is the array of photon types
organized by wavelength, energy, or frequency. Visible light is a
narrow band within this array.
 Law of Reflection at air-glass boundaries.
What skills will students learn as part of this unit?
 Identify a lens as positive or negative and convex or concave
or meniscus.
 Use the lens maker’s equation to predict the focal length of
a lens based on its radii of curvature and index of refraction.
 Using ray diagrams to predict the location of best image for
a given lens.
 Identify aberration type based on analysis of marginal,
paraxial, and chief ray intersections.
Based on UbD (ASCD) by G. Wiggins and J. McTighe
Subject: Precision Optics II Grade: 10-11
Unit #: 1
Title: Lens Function & Design
 Law of Refraction (Snell’s Law) at air-glass boundaries.
 Index of refraction is a measure of a glass’s optical density and
degree to which it can bend light.
 The lens maker’s equation ( = [n-1][1/R1 – 1/R2]) is used to
determine a theoretical focal length of a lens based on the radii of
curvature and index of refraction.
 Dispersive index is a measure of a glass’s ability to diffract light
differently according to color (dispersion).
 A glass map is a 2-D organization of glass types according to index
of refraction (at 589.3 nm) and dispersive index.
 Positive lenses cause light to converge. Negative lenses cause light
to diverge.
 Lenses can be convex, concave or meniscus.
 Optical engineers use ray diagrams to describe the motion of light
through an optical system.
 Marginal, paraxial, and chief rays are drawn to show different
aspects of light’s motion through an optical system.
East High School, Rochester, NY
Based on UbD (ASCD) by G. Wiggins and J. McTighe
Subject: Precision Optics II Grade: 10-11
Unit #: 1
Title: Lens Function & Design
STAGE TWO: Determine Acceptable Evidence
Evaluative Criteria
(T) Examine a series of ray diagrams
for different lens systems and
compare/comment on the predicted
quality of each lens’ image.
Performance Tasks:
Characterize the elements in an optical system and evaluate the design choices based on the types
of aberrations that exist in a ray diagram sketch.
1. (A) How completely does the student
know the EM spectrum?
2. (A/M) How well can a student
characterize what happens when rays
of light strike a plane surface?
3. (A/M) How well can a student
characterize what happens when rays
of light strike a curved surface?
4. (A) How well can a student ID a lens
type and function based on its shape?
5. How well can a student interpret a
glass map?
6. (A) How completely can a student
manipulate the lens maker’s equation
to predict the power and focal length
of a given lens?
7. (M) How well can a student identify
aberrations based on ray diagrams?
8. (T) How effectively can a student
weigh pros and cons to determine the
best fix for a given aberration?
9.
Other Assessment Evidence:
1. EM spectrum inventory. [What is light?]
2. Snell’s Law & reflection experiment with rectangular prisms. [How does light interact with matter]
3. Snell’s Law experiment and light through concave and convex prisms. [How does light interact with
matter?]
4. Illustrated Essay #1: What happens when light hits an air-glass boundary?
5. Lens shape and lens function identification worksheet. [Why does curve matter?]
6. Dispersion demo & glass map interpretation assignment. [Why does composition matter?]
7. Lens Maker’s Equation worksheet and Excel spreadsheet. [Why does curve & composition matter?]
8. Ideal Ray Diagram reading and questions. [What can we get away with when designing optics?]
9. Real Ray Diagrams & Lens Aberrations interpretation worksheet. [What can we get away with when
designing optics?]
10. Lens aberrations corrections worksheet. [How do optical designers maximize the performance of an
optical system?]
11. Illustrated Essay #2: What variables impact image quality and what choices determine the final lens
design? [What can we get away with when designing optics?]
East High School, Rochester, NY
Assessment Evidence
Based on UbD (ASCD) by G. Wiggins and J. McTighe
Subject: Precision Optics II Grade: 10-11
East High School, Rochester, NY
Unit #: 1
Title: Lens Function & Design
Based on UbD (ASCD) by G. Wiggins and J. McTighe
Subject: Precision Optics II Grade: 10-11
Code
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A/M
A/M
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M
A/M
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A/M
T
Unit #: 1
Title: Lens Function & Design
STAGE THREE: Plan Learning Experiences
Learning Events:
Evidence of learning: (formative assessment)
1. Investigating the EM spectrum: interactions between light and matter. 1. Analyze a situation and identify the type of EM
2. Light’s journey from air into and out of glass: What happens at the
radiation at play.
boundaries and in the bulk?
2. Qualitatively predict the path of light from air
3. Law of Reflection & Snell’s Law ‘plane’ experiment.
into glass and back into air and predict light’s
4. Law of Reflection and Snell’s Law ‘curved’ experiment
path when it reflects at a surface.
5. Identifying a lens type based on shape.
3. Accurately discuss and illustrate the principle
6. Fill in the box “before and after” light beams.
of dispersion and the dispersive index of glass.
7. Experiencing the dispersion of white light through prisms.
4. Correctly identify glass types based on
8. Reading and interpreting a Schott Glass Map and glass codes.
refractive and dispersive indices.
9. Comparing and contrasting two optical glass types.
5. Comparing and contrasting properties of two
10. Lens Maker’s Equation by hand and with Excel.
glass types from given glass codes.
11. Ideal Ray Diagram reading.
6. Calculate lens power and focal length from
12. Real Ray Diagrams lecture.
curvature and glass code.
13. Introduction to lens aberrations.
7. Match the change in light ray paths with the
14. Correcting lens aberrations.
appropriate lens shape.
15. Evaluating lens choices based on aberrations.
8. Match the correct aberration with ray diagram.
East High School, Rochester, NY
Based on UbD (ASCD) by G. Wiggins and J. McTighe